1. Field of the Invention.
The present invention relates generally to infiltration control devices and in particular to such a device for doors and windows.
2. Description of the Prior Art.
Weather sealing and weatherstripping devices are commonly provided around various openings in enclosures of various types wherein temperatures are maintained at different levels than exterior or ambient temperatures. Enclosures such as buildings generally include doors which open and close to allow ingress and egress. Operable windows may also be provided for ventilation, emergency egress, etc. Building codes generally specify minimum numbers and sizes of doors and operable windows, which are collectively referred to as fenestration.
In most buildings the fenestration is a major source of heat loss and heat gain; and in many residential dwelling units it is probably the single largest source. One reason for the relatively large thermal transfer through the fenestration is that the door and window materials--e.g. glass, aluminum, etc.--often have very low insulative values in comparison with other parts of the structure such as the walls and the roof. A second reason relates to air infiltration around the fenestration. The present invention deals with the latter source of thermal transfer.
The difficulties in providing weather-tight seals in doors and operable windows are well known, and a variety of different devices have heretofore been proposed which address this problem. For example, a common practice is to provide an elastomeric weatherstrip around all moving parts of doors and operable windows so that when they are closed the weatherstrip compresses and seals the gaps between the moving and non-moving parts. Although such weatherstrips are usually somewhat effective, it is often particularly difficult to achieve an effective airtight seal along the thresholds of doors and the sills of operable windows. Door and window openings as well as the units themselves often distort from their original configurations whereby gaps and leaks can occur which permit more infiltration. Such distortion can be caused by settlement of the structure itself which causes displacement between the openings and the fenestration units and also by warpage of the fenestration units. In wood-frame structures, such problems are particularly common, and represent a major cause of thermal transfer from conditioned air inside the structure escaping to the outside or from outside air entering the structure.
One type of prior art device designed to reduce thermal transmission at door thresholds and window sills comprises an unattached tube of flexible material, such as fabric, filled with an insulating material and placed adjacent to the inside edge of a door threshold or window sill. However, such devices interfere with the normal ingress and egress through a door and can prevent closure of a door or window if improperly placed.
Heretofore, there has not been available an infiltration control device with the advantages and features of the present invention.